Digital tape recording remains a viable solution for storage of massive amounts of data. Conventionally, at least two approaches are employed for recording digital information onto magnetic recording tape. One approach calls for moving the tape past a rotating head structure which records and plays back user information from discontinuous transverse tracks. Interactive servo systems are employed to synchronize rotation of the head structure with travel of the tape. Another approach is to draw the tape across a non-rotating head at a considerable linear velocity. This approach is sometimes referred to as linear “streaming” tape recording and playback.
Increased data storage capacity and retrieval performance is being required of all commercially viable mass storage devices and media. In the case of linear tape recording, a popular trend is toward multi-head, multi-channel fixed head structures with narrowed recording gaps and track widths. Such narrow recording heads allow many linear tracks to be formed on a tape medium of predetermined width, such as one-half inch width tape. Tape substrates are also being made thinner, with increased tape lengths being made possible in small diameter reel packages.
Because of a relatively high linear tape velocity and because tape substrates continue to be made thinner and thinner, guiding tape past a tape head structure along an accurate invariant linear path has proven to be highly problematical. One error phenomena is known as “lateral tape motion” or “LTM.” LTM is a major source of tracking errors in linear tape recording. One proposed approach to minimizing LTM tracking errors includes printing servo tracks onto the tape, to allow a control system to maintain fine control over the alignment between the recording head and data tracks associated with the servo tracks. Such a system is described in the above identified U.S. patent application “Multi-Channel Magnetic Tape System Having Optimal Tracking Servo.”
As described therein, a system can compensate for lateral tape movement by employing a servo mechanism to record data onto a magnetic tape that is preformatted with a suitable servo pattern. Such pre-formatting allows a user to insert a tape into an existing tape drive and immediately begin recording data without having to first format the tape, thus avoiding what can be a time consuming process. Thus, preformatted tapes can hold more data and save time for a user. However, the success of the system depends in part on the ability to accurately format a tape with a set of servo tracks.
Thus, there is a need in the act for systems that can accurately and efficiently format a magnetic tape with one or more servo tracks.